Mechanical freezing tray and method of operating same



H. D. GEYER 2,576,591

MECHANICAL FREEZING TRAY AND METHOD OF'OPERATiNG SAME Nov. 27, 1951 3 Sheets-Sheet 1 Filed June 26, 194'? INVENTOR. ABVE-YD. GE'YE'B H. D. GEYER Nov. 27; 1951 MECHANICAL FREEZING TRAY AND METHOD OF OPERATING SAME 3 Sheets-Sheet 2 Filed June 26, 194'? d/lwuw HM FK H- D. GEYER Nov. 27, 1951 MECHANICAL FREEZING TRAY AND METHOD OF OPERATING SAME Filed June 26, 194'? 3 Sheets-Sheet 5 m wr 24 INVENTOR. Mae VE-Y D. Gas 5e BY '%.M

Patented Nov. 27, 1951 UNITED STATES PATENT OFFICE MECHANICAL FREEZING TRAY AND METHOD OF OPERATING SAME Harvey D. Geyer, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 26, 1947, Serial No. 757,288

of movable partition walls .whichldivide the frozen contents into ice blocks of suitable size, and having an ice-motor unitautomatically actuated by the expansion force obtained by the freezing of a contained liquid for moving said part1:- tion wall and thereby automatically loosening the ice blocks from said gridwhile. thetray and contents remain in the freezing compartment.

The ice tray of this invention, after being filled with water to the proper level, is. simply placed in the freezing compartment and the water con tents allowed to freeze into solid ice blocks in a normal manner. Shortly after said ice blocks are frozen the water, or other suitable liquid, con-' fined in the ice-motor unit freezes and expands and thereby forces out a piston. or similar moving part, on the ice-motor with a movement capable of-overcoming a great resistance. Such piston movement is used to move the relatively movable partition walls of the grid in such a way as to mechanically loosen the iceblocks from both the container pan and the partition walls. After such automatic looseni takes place the loose ice blocks may be individually removed from the tray with the fingers or be dumped therefrom, or the removable grid may be lifted from the pan leaving the loose ice blocks in the pan.

Heretofore there have been devised many forms of mechanical ice trays having relatively movable partition walls which are moved by a hand lever, or the like, for loosening the frozen ice blocks therefrom without the aid of heat. By this invention the relatively movable partition walls of mechanical ice trays are automatically moved to loosen the ice blocks by the expansion force of a confined liquid which freezes and expands after the ice blocks are frozen solid. It is preferred that he actuation of the ice motor unit of this inve tion be delayed until the ice blocks are frozen solid. If the confined liquid in the ice-motor freezes and expands while the ice blocks are only partially frozen the actuating movement of the ice-motor will occur too soon and may crush the partially frozen ice blocks. If so desired, the delay in the freezing of the confined liquid in the ice-motor unit may be obtained simply by using a suitable liquid having a freezing point somewhat below 32 F., for instance, water with sufficient alcohol added thereto to give the desired delay in freezing. Also I Claims. (Cl. 62-}08-5) such desired delay may be obtained with ordinary drinking water confined in the ice-motor by locating the ice-motor above and in the proximity of that portion of the ice blocks which is the last to freeze, so that the liquid confined in the icemotor will normally freeze only after the ice blocks are fully frozen. One object of this invention is to provide a freezing tray having an ice-motor unit for automatically loosening the frozen ice blocks contained therein by the expansion force due to the freezing of a liquid contained in the ice-motor, wherein the freezing of the liquid contained in the ice-motor is delayed until after the ice blocks have been fullyfrozen.

Another object of this invention is to provide a freezing tray having an ice-motor for automatically loosening the tray container from its frozen bond to its supporting surface in the freezing compartment after the ice blocks have been frozen, whereby to permit easy removal of the tray from the freezing compartment.

Another ,object is to provide a freezing tray having an ice-motor for automatically performing the two functions, namely for loosening the frozen ice blocks from the tray and for loosening the tray itself from its frozen bond to its supporting surface.

Other features of the freezing tray herein disclosed are the simplicity and efllciency of the mechanical arrangement whereby the ice-motor (1) positive actuates the relatively movable grid walls to oosen the individual ice blocks from the tray, and (2) positively actuates a lifting lever to loosen the container pan from the supporting shelf. An important feature is the automatic return to their original freezing position of all the movable parts when the grid is inserted without special care into the pan at the start of any freezing operation. 7

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein the preferred embodiment of the invention is clearly shown.

In the drawings:

Fig. 1 is a plan view of an empty grid and. pan embodying this invention, all the parts being in freezing position.

Fig. 2 is a vertical section on line 22 of Fig. 1.

Fig. 3 is a plan view similar to Fig. 1, but shows the positions of the parts after the ice-loosening actuation of the ice-motor. The ice blocks have been omitted in Fig. 3 for sake of clearness.

'Fig. 4 is a vertical section on line 44 of Fig. 3. and illustrates the loosened position of the ice blocks after actuation of the ice-motor.

Fig. 5 is a detail view of the longitudinal center wall of the grid.

Fig. 6 is a detail view of any one of the cross walls of the grid.

Figs. 7, 8 and 9 are detail views of the particular form of ice-motor unit which has been chosen for illustrative purposes.

Fig. 7 is a longitudinal section thru the center line of the ice-motor unit, and shows the parts in their initial position before expansion takes place.

Fig. 8 is a view similar to Fig. 7 but shows the parts in position after the liquid confined therein has frozen and pushed the actuating piston to its outermost. position.

Fig. 9 is a view on an enlarged scale showing spaced cross walls 22 each loosely mounted upon main wall 2| so as to be capable of a relative tilting movement with respect to said wall 2|. Wall 2| has a series of open slots 23 extending upwardly from its bottom edge to loosely receive the continuous portions 24 of cross walls 22, and 1 cross walls 22 have open slots 25 therein which loosely receive the continuous portions 26 of main wall 2| above slots 23. Slots 23 are preferably shaped with a suitably inclined rear edge 21 so that when cross walls 22 are tilted back against these inclined edges 21 to their inclined freezing positions the lower margin of each cross wall 22 will abut the opposed forward edge 28 of its slot 23. By this means the rearward tilting movement of cross walls 22 is limited so that all of cross walls 22 will be rearwardly inclined at the desired angle when the grid parts are in their freezing positions, as shown in Fig. 2.

The cross walls 22 are retained against dropping out of slots 23 by gravity (when the grid is lifted from the pan) by the actuating bar 38 which overlies the main central wall 2| and is mounted thereupon so as to have a fore and aft sliding movement. Actuating bar 30 fits loosely within the wide notches 3| cut in the upper central portions of cross walls 22 and each cross wall 22 has a small laterally projecting tongue 32 which overlies one marginal edge of bar 30. Thus the cross walls are retained against dropping entirely out of slots 23 in main wall 2| when the empty grid is handled apart from the pan l3. Actuating bar has a central slot 33 near its forward end which fits loosely about an upstanding projection 34 on main wall 2|. After this projection 34 is passed thru slot 33 during assembling of the grid parts as described below, the small tongue 35 on projection 34 may be readily bent laterally (see Figs. 1 and 3) to retain these parts assembled together at the forward end of the grid. Actuating bar 30 has another slot 36 adjacent its rear end within which the upstanding projection 31 on main wall 2| has a loose sliding fit. The central portion of actuating bar 30 is cut away to provide an elongated opening 40 having such dimensions as to suitably receive the elongated ice-motor unit 80, as hereinafter described. Slot 38 in bar 30 extends through into one end of the large central opening 40 (see Figs. 1 and 3). Actuating bar 33 has a series of pairs of notches 33 cut in its lateral margins, each pair of notches 38 receiving one of the cross walls 22 and by means of which the cross walls may be tilted either forwardly or rearwardly when bar 38 slides forwardly or rearwardly.

These pairs of notches 38 preferably progressively increase in their longitudinal dimension from the forwardmost cross wall 22 to the rearmost cross wall 22, so that the forwardmost cross' wall will be tilted forward first and the other cross walls will be tilted forward successively from front to rear, as will be clear from Figs. 2 and 4.

The grid parts so far described may be assembled as follows. Cross walls 22 are first assembled upon main wall 2| and held in a substantially vertical position by means of a suitable assembling fixture. Then the actuating bar 30 is inserted in the wide notches 3| in the cross walls. This may be done by first registering its notches 38 with all the cross walls and by tilting bar 30 laterally so that one marginal edge thereof can be inserted under all the aligned tongues 32 of the cross walls, while at the same time the opposed vertical edges of notches 3| on the cross walls enter their registering notches 38 on bar 33. Then the bar 30 can he slipped down over the upstanding projections 34 and 31 on main wall 2| because these projections will then be in registration with slots 33 and 38 respectively on bar 38. Then the tongue 38 on upstanding projection 34 is bent laterally, as

shown in Figs. 1 and 3, to overlie bar 33 and a exceeds the longitudinal dimension of the neck portion of projection 34 a sufllcient amount to permit the desired to and fro sliding movement of bar 30. Figs. 1 and 2 show bar 30 moved to its rearmost or freezing position, and Figs. 3. and

4 show bar 30 moved to its normal forward position with all the cross walls 22 tilted forward and the ice cubes loosened.

Container pan III has a suitable combination lifting cam and handle 80 pivotally mounted upon its front end as shown in Figs. 2 and 4. A small bracket 8| is rigidly fixed to the end of pan l0. preferably by spot welding, and handle 88 is pivoted to bracket 8| by pivot pin 82. When handle 80 is in the upright position shown in Fig. 2, its camming portion 83 lies flush with the bottom surface of pan l8 and hence will merely contact the supporting surface upon which pan l0 rests. When handle 88 is swung about its pivot pin 82, to the left as shown in Fig. 4, its camming portion 83 will bear down upon the refrigerated shelf (indicated by line 84 in Fig. 4) upon which pan l0 rests and thus pry the front end of pan i0 upwardly from its supporting shelf. The actuating bar 30 of the grid has a depending portion 33 at its front end which abuts handle 80 when handle 80 is in its upright position and all the grid parts are in their freezing position, as shown in Fig. 2. Now when actuating bar 38 is moved to the left (as viewed in Figs. 1 to 4) by the ice-motor 58 to loosen the icecubes. as hereinafter described, portion 35 of bar 38 will force handle 88 to swing about its pivot pin 82 and thus cam pan l8 upwardly from its supporting shelf 85, as shown in Fig. 4. Thus pan l8 will be automatically freed from its frozen bond to its supporting shelf by the operation of the ice-motor 58 whenever said ice-motor forces actuating bar 38 to slide horizontally to the left to loosen the ice cubes. A suitable return spring for handle 88 is provided,,s,uch as the 'coil spring 85 which has one end 88 attached to handle 88 and its other end 81 attached to bracket 8|. Spring 85 at all times urges handle 88 to return to its correct freezing position as shown in Fig. 2, which in turn urges the actuating bar 38 to return to its freezing position, and this in turn causes the cross walls 22 to return to their correct freezing positions, whenever the grid is inserted into the pan I 8 at the start of any freezing operation. Hence the grid may be simply inserted into the pan without special care and all the movable parts will automatically move to their correct freezing positions.

The ice-motor of this invention is, broadly, a suitably strong container closely confining a volume of liquid which will freeze and expand with a potentially very large force, and means for harnessing this force and the increase in volume of the liquid upon freezing to displace a movable piston, bellows, diaphragm, or the like, through a substantial distance to perform useful work upon any sort of device or mechanism. When a container is completely filled with water and subjected to temperatures below its freezing point, the confined water will build up a tremendous internal pressure in its effort to expand upon freezing. Such internal pressure is potentially about 1100 lbs. per sq. inch at 31 F., twice that at 30 F., three times that at 29 F., etc. Of course when the piston or diaphragm of the container moves and permits expansion the internal pressure does not exceed that necessary to move the piston.

The specific form of ice-motor chosen for illustration of this invention will now be described. An elongated metal tube 5| is closed and sealed at one end thereof by the metal cap 52 strongly fixed thereto by screw threads or the like. A metalcylinder member 53 is similarly fixed to the opposite end of tube 5| by screw threads 5|a. Within bore 54 of cylinder 53 an elongated metal piston 55 fits with a snug sliding fit in order to prevent leakage between piston 55 and bore 54.

Piston 55 has an integral exterior head 58 which abuts the end of cylinder 53 when the piston is at its inmost position (see Fig. 7). Preferably piston 55 is provided with a ring groove 58 and a suitable piston ring 51 in order to more positively seal the contents within-tube 5|. The seal ring 51 may be of any suitable type, however it is preferred to use an endless rounded section soft rubber ring 51 which is only slightly compressed within the groove 58 substantially as illustrated on an enlarged scale in Fig. 9. Such a ring 51 seals by distortion thereof by the fluid pressure against either side thereof within groove 56. This will effectively prevent leakage of water or air past the piston 55 in either direction. Also such a ring 51 normally presents little friction against the cylinder bore 54 and so will not prevent the automatic inward movement of piston 55 as the ice in tube 5| melts and tends to create 4 a partial vacuum therein due to the contraction in volume when ice changes to water. In order to further insure the automatic inward movement of piston 55 and to prevent the creation of a partial vacuum in tube 5| as the ice therein melts, the coil tension spring 58 is preferably provided which will yieldingly urge piston 55 to its inmost position shown in Fig. '7. The tension on coil spring 58 is preferably somewhat greater than the friction or other forces Opposing such inward movement of piston 55, so that the inwardly moving piston will closely follow up the contracting volume of ice and water in tube 5| as the ice melts, and thus prevent any leakage of outside air into tube 5| during such melting.

The operation of the ice tray here chosen for illustration by the ice-motor 58 is as follows. Tube 5| may be completely filled with ordinary drinking water simply by withdrawing piston 55 entirely from its cylinder 53, which can be readily done by grasping the piston head 58 with the fingers and stretching the long coil spring 88 sufficiently, to permit water to flow into the open end of cylinder 53. After all air bubbles have risen with the unit held in upright position, piston 55 is reinserted in bore 54 and forced down against the trapped water to its inmost position shown in Fig. 7. During such forcing the excess water in tube 5| may be forced out of a minute vent opening provided for that purpose and Subsequently closed. Tube 5| will then be completely filled with water and may be freely handled in that condition without leakage and with piston 55 the length of unit 58. Therefore the piston head 58 of unit 58 will abut the forward edge of upstanding projection 31 on main wall 2|, and the closure cap 52 at the opposite end of unit 58 will abut the edge 43 of opening 48. Preferably the cylindrical outer surface of cap 52 and cylinder 53 of unit 58 are knurled and have a snug friction fit within opening 48 in actuating bar 38, so that after unit 58 has been inserted in its opening 48 the grid alone or the grid and pan together may be quite freely handled without dis,- locating unit 58 from its proper position therein. Of course unit 58 may be positively attached to actuating bar 38 by any suitable fastening means rather than be retained in place by a friction lit. The gridwith unit 58 properly retained in place may be placed in pan |8 or removed therefrom at will at any time without special care in handling. The pan is filled with water to such a level that unit 58 will normally lie adjacent to but out of contact with the water in the upper central portion of pan |8.

The entire device is then set within a freezing compartment, usually upon a refrigerated shelf so that most of the heat transfer takes place thru the walls of pan l8. The water in pan |8 will heat conduction path to pan I0. Unit 50 loses its heat chiefly to the surrounding cold air, and

such heat transfer takes place much more slowly than the conduction of heat thru the metal pan directly to the refrigerated metal shelf.

After the ice cubes in pan l are frozen the pure water confined in tube gradually freezes and expands in volume to about 1.0855 of its original volume. This increase in volume will force piston 55 outwardly, with a force capable of overcoming a very high resistance, to the final position shown in Figs. 3, 4 and 8. Since head 58 of piston 55 abuts projection 31 on main wall II and the opposite end 52 of the unit 50 abuts edge 45 of the actuator bar 30, the actuator bar 50 will be forced to move to the left (as seen in Figs. 3 and 4) relative to main wall II. In other words. the elongation of the ice-motor 50 causes a relative sliding movement between main wall 2| and actuator bar 30. Such relative sliding movement of bar 30 causes its notches 38 to engage and first slightly flex and then bodily tilt the cross walls 22 forward, in succession one after the other, to loosen the ice blocks from both the pan and the grid, substantially as illustrated in Fig. 4. When each cross wall 22 is tilted forward it seems to first peel from the ice in which it is embedded by a slight flexing thereof and thereafter swings forward bodily to move the two ice cubes immediately in front of same, as illustrated in Fig. 4.

As actuator bar 80 moves forward, its depending portion 39 immediately engages and swings lever 80 forward about its pivot pin 52 and so causes cam portion 53 to pry pan it loose from its frozen bond to,its supporting shelf indicated by line 54 in Fig. 4. Therefore any time after icemotor 50 has been actuated by the freezing of its confined liquid, the loose ice tray may be readily removed from its freezing compartment and the already loosened ice cubes will be readily available for instant use. The loose ice cubes may be individually removed by suitable tongs or by hand, but preferably the entire grid is simply lifted up from the pan and the loose ice cubes permitted to slide from the grid by gravity and remain in the pan.

If so desired, all the ice cubes may be removed and the pan refilled with water for the next freezing operation within a minute or two after.

the tray is removed from the refrigerator. Of course the contents of the ice-motor 50 must again melt to the liquid state before all the movable parts return to their exact freezing positions shown in Figs. 1 and 2. Since tube 5| is metal and hence has high heat conductivity and has only a small diameter it will require only several minutes for the long slim stick of ice therein to melt under ordinary room temperature after its removal from the refrigerator. Ordinarily by the time the housewife takes care of the ice cubes from the first freezing and refills the pan with yvater to be frozen, the ice in tube 5| will hav melted and the piston 55 again drawn into i inmost position by its tension spring 55. But it is not necessary to wait for piston 55 to reach its inmost position before the newly filled tray is set back into the refrigerator. This, because the ice in tube 5| will complete its melting due to its proximity to the relatively warm water in pan l0 shortly after the tray is set back into the refrigerator and thereupon all the movable parts will automatically return to their correct freezing position due to the urge of coil spring 85 on handle 50, as described hereinabove.

- 8 It will be noted from Fig. 4 that after the ice-motor 50 has operated and loosened the ice cubes, the cubes remain cocked at an angle to the bottom of pan It. It is also obvious that the loosened cubes will not then lie in a conforming surface to surface contact with the outwardly tapered side walls of pan l0, nor in fact with any of the grid partitions because of their general looseness. This will prevent, or at least greatly reduce, any tendency of the loosened ice blocks to again bond themselves tightly to the pan or grid if left undisturbed in the freezing compartment for quite a period, say two weeks or more.

The specific form of ice-motor unit 50 herein described for the purpose of illustrating the invention may be varied in many ways without departing from the teachings of this invention. An expansion piston, similar to piston 55, may be used at both ends of tube 5| if such construction be desired for any reason. Also a hermetically sealed Sylphon bellows or other suitable form of flexible diaphragm may be substituted for the sliding piston to transmit the expanding force of the confined liquid when it freezes. If so desired, a hermetically sealed elastic tube of rubber, or the'like, may be closely fitted into tube 5| and attached to the inner end of piston 55 so as to hermetically seal the confined iiquid in tube 5| and thereby eliminate all possibility of leakage of the confined liquid. Such an elastic tube may be molded with one open end like a soft rubber bag in a fountain pen, and its originally open end closed by being clamped around and sealed to the inner end of piston 55 after said tube is filled with the proper volume of freezing liquid. The filled elastic tube should closely fit the confining walls of tube 5| so that substantially all increase in volume of the confined liquid upon freezing will be permitttied only by an outward displacement of the pisn. What I claim is as follows: i

1. In afreezing device, in combination, a container pan, a removable grid insertable within said pan and having a plurality of relatively movable partitions for dividing the frozen contents of the pan into ice blocks, and a unitary ice-motor carried by said grid and containing a freezing liquid, said unitary ice-motor having reaction members which are forced to move relatively to each other when said liquid freezes and expands, said reaction members being arranged to react between relatively movable portions of said grid for moving said partitions relative to each other to loosen said ice blocks after they are frozen.

2. In a freezing device, in combination, a container pan, a removable grid for said pan having a plurality of relatively movable partitions for dividing the frozen contents of the pan into ice blocks, and a unitary ice-motor carried by said grid and containing a freezing liquid, said icemotor having reaction members which are forced to move in opposed directions'when said liquid freezes and expands, said reaction members being arranged to react between and force relatively movable portions of said grid in opposed directions for loosening the frozen ice blocks.

3. In a freezing device, in combination, a con- .tainer, a plurality of relatively movable partitions for dividing the frozen contents of said container into smaller pieces, a mechanism including an actuating bar arranged to move said partitions relative to each other to loosen the frozen ice pieces, and an ice-motor containing a freezing liquid and having two reaction members moved relatively in opposed directions by the force of expansion of said freezing liquid upon freezing thereof, said reaction members being arranged to react between opposed portions of said grid to move said actuating bar and thereby move said partitions relative to each other.

4. In a freezing device, in combination, a container pan, a removable grid having a plurality of relatively movable partitions for dividing the frozen contents of the pan into ice blocks, and a unitary ice-motor carried by the grid and operated by the freezing of a trapped liquid, said ice-motor having members moved relatively in opposed directions by the freezing and expansion of said trapped liquid after said ice blocks are frozen, said members being arranged to react between portions of said grid to move said partitions relative to each ether to loosen the ice blocks.

5. In a freezing device, in combination, a container, a plurality of relatively movable partitions for dividing the frozen contents of said container into smaller pieces, a longitudinally movable actuating bar arranged to move said plurality of partitions relative to each other to loosen the frozen ice pieces, and an ice-motor operated by the freezing of a trapped liquid, said ice-motor being arranged to react between said actuating bar and one of said partitions for moving said actuating bar longitudinally.

6. In combination, a mechanism and an icemotor for automatically operating said mechanism, said ice-motor comprising a substantially non-expansible container completely filled with a confined freezing liquid, said ice-motor having a work cylinder and a sliding piston therein, the increase in volume of said confined liquid upon freezing serving to force said piston outwardly with a potential pressure per square inch thereupon substantially equal to the maximum pressure exertable by said liquid upon freezing.

'7. In a freezing device, in combination, a container ice pan, a removable grid insertable within said pan and having a plurality of relatively movable partitions for dividing the frozen contents of said pan into ice blocks, and a separate unitary grid-actuating motor carried by said grid and having reaction members which are forced to move in opposed directions at a predetermined temperature, said reaction members being arranged to react between relatively movable portions of said grid for moving said partitions relative to each other to loos-en said ice blocks after they are frozen.

HARVEY D. GEYER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 921,370 Degener May 11, 1909 989,044 Pool Apr. 11, 1911 2,058,458 Hull Oct. 27, 1936 2,066,042 Knight Dec. 29, 1936 2,133,860 Hill Oct. 18, 1938 2,181,580 Fitzsimmons Nov. 28, 1939 2,341,700 Diack Feb. 15, 1944 

